In part it's because Claxter behaves as an idealist surrounded by pirates, thieves, bounty hunters, and terrorists. In his defense, he's finally onboard a ship where this behavior makes vaguely more sense and Keshin dicking around with Salem actually IS a security risk.
But yeah, the majority population of the Bar and Rogue Element are those who do not trust anyone but their own kin. They're not so much "too cynical" as "understandably cynical." Examples: Keshin has alternatively worked for and tried to kill members of the Rebellion, all depending upon who was paying them and for what. Efaen has attempted to genocidally off everyone in the entire Rebellion, although she doesn't remember this. In another case, half of the current Rebellion members are actually from another Rebellion that split from or was never a part of the main branch.
Yeerks....have it rough. And Keshin's still pretty racist. X)